Britain’s Defence Secretary John Healey resigned on Thursday (June 11, 2026), citing inadequate defence spending by the Keir Starmer-led Labour government.

The resignation further weakens Mr. Starmer, who has been overwhlemed by internecine battles and will potentially have to face a leadership contest in the coming months.

New threats faced by the U.K. required further investment through the Defence Investment Plan (DIP) , Mr. Healey said. This had been confirmed by the Labour government. Yet, since this funding assessment was made in January, Mr. Starmer was “unable, and the Treasury has been unwilling” to commit the required resources needed, Mr. Healey wrote in his resignation letter, which was posted on X.

The U.K.’s defence challenges had in fact grown since January, Mr. Healey said, citing among others, the conflict in West Asia, the U.K. “leading the multinational Strait of Hormuz military mission”, High North security, and the U.K. leading NATO’s Arctic Sentry mission.

Part of Mr. Healey’s criticism was that the government was not ramping up defencing spending fast enough to meet its committed expenditure as per the DIP.

U.K. to increase defence spending to 2.5% of GDP during 2027

Under pressure from U.S. President Donald Trump, the U.K — like other NATO countries — had agreed to increase defence expenditure, spending 3.0% of GDP by 2030 and 3.5% by 2035.

NATO defence ministers are due to meet in Brussels next Thursday (June 18, 2026).

This is the latest in a series of resignation from the government in weeks. Health Secretary Wes Streeting had resigned in May and indicated that he would run in any contest for No. 10 Downing Street.

Greater Manchester Mayor Andy Burnham, seen as the strongest contender to Mr Starmer, is contesting a byelection in Makerfield, in the North West of England, on June 18. A win there would bring him to Westminster, a necessary step if he wishes to challenge the Prime Minister.